s390/qdio: Cleanup error handling to drivers

Various improvements of qdio error reporting to the
upper-layer drivers (qeth, zfcp):

- Split QDIO_ERROR_ACTIVATE_CHECK_CONDITION into:

  QDIO_ERROR_ACTIVATE: qdio termination interrupt
  QDIO_ERROR_GET_BUF_STATE: QIOASSIST eqbs error
  QDIO_ERROR_SET_BUF_STATE: QIOASSIST sqbs error

  Add QDIO_ERROR_FATAL / QDIO_ERROR_TEMPORARY masks
  to ease recovery decision in upper-layer drivers.

- Don't (ab-)use qdio handler errors as return codes
  for do_QDIO but use standard error codes:

  -ENOBUFS: temporary target CC=2 condition
  -EBUSY: unresolved SIGA-W CC=2 busy condition
  -EIO: I/O error (CC=1, CC=3)

- Remove unneeded memory clobber from SIGA-R
- Remove EX_TABLE entry on SIGA-W, we want to see these errors

Reviewed-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/net/qeth_core_main.c

@@ -3339,7 +3339,7 @@ static void qeth_flush_buffers(struct qeth_qdio_out_q *queue, int index,
 	if (rc) {
 		queue->card->stats.tx_errors += count;
 		/* ignore temporary SIGA errors without busy condition */
-		if (rc == QDIO_ERROR_SIGA_TARGET)
+		if (rc == -ENOBUFS)
 			return;
 		QETH_CARD_TEXT(queue->card, 2, "flushbuf");
 		QETH_CARD_TEXT_(queue->card, 2, " q%d", queue->queue_no);
@@ -3533,7 +3533,7 @@ void qeth_qdio_output_handler(struct ccw_device *ccwdev,
 	int i;
 
 	QETH_CARD_TEXT(card, 6, "qdouhdl");
-	if (qdio_error & QDIO_ERROR_ACTIVATE_CHECK_CONDITION) {
+	if (qdio_error & QDIO_ERROR_FATAL) {
 		QETH_CARD_TEXT(card, 2, "achkcond");
 		netif_stop_queue(card->dev);
 		qeth_schedule_recovery(card);